Material flammability is an important factor in determining the pressure and composition (fraction of oxygen and nitrogen) of the atmosphere in the habitable volume of exploration vehicles and habitats. The method chosen in this work to quantify the flammability of a material is by its ease of ignition. The ignition delay time was defined as the time it takes a combustible material to ignite after it has been exposed to an external heat flux. Previous work in the Forced Ignition and Spread Test (FIST) apparatus has shown that the ignition delay in the currently proposed space exploration atmosphere (approximately 58.6 kPa and 32% oxygen concentration) is reduced by 27% compared to the standard atmosphere used in the Space Shuttle and Space Station. In order to determine whether there is a safer environment in terms of material flammability, a series of piloted ignition delay tests using polymethylmethacrylate (PMMA) was conducted in the FIST apparatus to extend the work over a range of possible exploration atmospheres. The exploration atmospheres considered were the normoxic equivalents, i.e. reduced pressure conditions with a constant partial pressure of oxygen. The ignition delay time was seen to decrease as the pressure was reduced along the normoxic curve. The minimum ignition delay observed in the normoxic equivalent environments was nearly 30% lower than in standard atmospheric conditions. The ignition delay in the proposed exploration atmosphere is only slightly larger than this minimum. In terms of material flammability, normoxic environments with a higher pressure relative to the proposed pressure would be desired.


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    Titel :

    Ignition Delay of Combustible Materials in Normoxic Equivalent Environments


    Weitere Titelangaben:

    Sae Technical Papers


    Beteiligte:
    Fernandez-Pello, Carlos (Autor:in) / Urban, David (Autor:in) / Ruff, Gary (Autor:in) / McAllister, Sara (Autor:in)

    Kongress:

    International Conference On Environmental Systems ; 2009



    Erscheinungsdatum :

    12.07.2009




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch


    Schlagwörter :


    Ignition Delay of Combustible Materials in Space Exploration Atmospheres

    Fernandez-Pello, Carlos / Urban, David / Ruff, Gary et al. | SAE Technical Papers | 2008


    Ignition Delay of Combustible Materials in Space Exploration Atmospheres

    McAllister, S. / Fernandez-Pello, C. / Ruff, G. et al. | British Library Conference Proceedings | 2008


    Ignition of Combustible Fluids by Heated Surfaces

    Bennett, J. M. / Ballal, D. R. / AIAA | British Library Conference Proceedings | 2003


    Ignition Process of Compound Spray Combustible Mixtures

    Arai, M. / Yoshida, H. / Hiroyasu, H. et al. | British Library Conference Proceedings | 1993


    Ignition of Combustible Fluids by Heated Surfaces

    Bennett, J. M. / Ballal, D. R. / AIAA | British Library Conference Proceedings | 2003